1. Field of the Invention
The present invention relates to a method of manufacturing a display which is formed by arranging small diffraction gratings on a two-dimensional plane in units of dots.
2. Description of the Related Art
Displays having diffraction grating patterns have been widely used. Such a diffraction grating pattern is formed by arranging a plurality of small dots consisting of diffraction gratings on a surface of a flat board. For example, Published Unexamined Japanese Patent Application No. 60-156004 discloses a method of manufacturing a display having a diffraction grating pattern of this type. In this method, small interference fringes (to be described as diffraction gratings hereinafter) produced by interference of two laser beams are sequentially exposed on a photosensitive film while the pitch and direction of the diffraction gratings and the light intensity are changed.
Recently, the present inventor has proposed a method of manufacturing a display on which a diffraction grating pattern having a certain graphic pattern is formed. In this method, an X-Y stage on which a flat board is placed is moved under the control of a computer so as to arrange a plurality of small dots consisting of diffraction gratings on a surface of the board. This method is disclosed in U.S. Ser. No. 276,469 on Nov. 25, 1988, now U.S. Pat. No. 5,058,092.
In such a method of manufacturing a display, however, an image input by an image scanner or the like, a two-dimensional image formed by computer graphics, or the like is used as a graphic pattern for a display having a diffraction grating pattern. Since a graphic pattern expressed by a diffraction grating pattern is positioned on a plane of a board on which diffraction gratings are arranged, only a two-dimensional graphic pattern can be expressed, but a panorama parallax or three-dimensional graphic image cannot be expressed.